Chartplotter turning off

martinriches

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When I use the bowthruster the Chartplotter turns itself off. They are both powered from the house battery's . Is there is a simple solution to this ?


Martin
 
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If you only use your bow thruster when the engine is running, then another way around it is to re-wire your bow thruster to run off the engine battery.
Quick and easy to do, no extra weight, no extra battery.
George
 

Bru

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Wot Sailorman said

Also, it may indicate that your service battery(s) is/are getting tired especially if the problem has developed recently when previouslly all was well
 

johnalison

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This used to happen with my Decca every time I started the engine and it took nearly 20 mins to find itself again. Other people had the same problem and one solution was to wire a small battery to the set which would cut in when needed. I can't remember exactly how it was done but it worked for some boats.
 

martinriches

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This used to happen with my Decca every time I started the engine and it took nearly 20 mins to find itself again. Other people had the same problem and one solution was to wire a small battery to the set which would cut in when needed. I can't remember exactly how it was done but it worked for some boats.

I think a small battery for the instruments charged from the house batterys via a vsr could be a good idea. I don't want to change the bowthruster arrangement as it works well.

Martin
 

pvb

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I think a small battery for the instruments charged from the house batterys via a vsr could be a good idea. I don't want to change the bowthruster arrangement as it works well.

Some would say the bowthruster arrangement doesn't work well! GeorgeLlewellyn's suggestion of rewiring the thruster to the start battery is probably the easiest solution. If you add a dedicated battery for the plotter/instruments, make sure it's a big one, as they can consume a lot of power on a long sail.
 

salar

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Some would say the bowthruster arrangement doesn't work well! GeorgeLlewellyn's suggestion of rewiring the thruster to the start battery is probably the easiest solution. If you add a dedicated battery for the plotter/instruments, make sure it's a big one, as they can consume a lot of power on a long sail.

You only need a small battery to avoid the voltage drop as the bow thruster cuts in. I had the same problem with my chartplotter cutting out when I started the engine so I fitted a sealed 12v battery from Maplins which I think is used in burgular alarms, plus a diode to keep the voltage in the right place! It worked well, then I did the right thing and fitted a proper dual battery set-up.
 

pmagowan

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So how does it get charged whilst sailing?
I think the point is that the instruments remain connected to the house battery just that they also have a parallel small battery near to them that prevents the volt drop that causes them to cut out. A diode prevents the thruster from 'stealing' this power also. As the battery is in the loop, so to speak, it remains charged by the same source that charges the house battery. A way to think of it is that a little bit of the house battery capacity is moved closer to, and dedicated to the instruments. Imagine this increases the house battery capacity to 110%. All 110% is available to the instruments but only 100% is available to the thruster.
 
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pvb

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I think the point is that the instruments remain connected to the house battery just that they also have a parallel small battery near to them that prevents the volt drop that causes them to cut out. A diode prevents the thruster from 'stealing' this power also. As the battery is in the loop, so to speak, it remains charged by the same source that charges the house battery. A way to think of it is that a little bit of the house battery capacity is moved closer to, and dedicated to the instruments. Imagine this increases the house battery capacity to 110%. All 110% is available to the instruments but only 100% is available to the thruster.

But the diode will further reduce the voltage available to the plotter. It's not a solution.
 

Ammonite

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This is a cheap and cheerful solution. Loads available on ebay with a range of specs for a few quid. Just keep it away from your VHF as they can produce interference. My garmin plotter is very sensitive to voltage drop and used to switch off when i started the engine. The previous garmin was fine so some are clearly more sensitive than others

http://m.ebay.co.uk/itm/4-35V-to-1-...CV-Voltage-Regulator-/301724461372?nav=SEARCH
 

martinriches

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I think the point is that the instruments remain connected to the house battery just that they also have a parallel small battery near to them that prevents the volt drop that causes them to cut out. A diode prevents the thruster from 'stealing' this power also. As the battery is in the loop, so to speak, it remains charged by the same source that charges the house battery. A way to think of it is that a little bit of the house battery capacity is moved closer to, and dedicated to the instruments. Imagine this increases the house battery capacity to 110%. All 110% is available to the instruments but only 100% is available to the thruster.

What sort of diode would I need and were would it go?

I was thinking of a small battery like this http://www.batterymegastore.co.uk/product/Y3.2-12/

Martin
 

Boo2

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This is a cheap and cheerful solution. Loads available on ebay with a range of specs for a few quid. Just keep it away from your VHF as they can produce interference. My garmin plotter is very sensitive to voltage drop and used to switch off when i started the engine. The previous garmin was fine so some are clearly more sensitive than others

http://m.ebay.co.uk/itm/4-35V-to-1-...CV-Voltage-Regulator-/301724461372?nav=SEARCH
Imho that's not enough power to be safe. I would want an output capacity of 6A @ 12V == 72W min to power a chartplotter, more if the CP's power spec suggested it.

Boo2
 
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Ammonite

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Imho that's not enough power to be safe. I would want an output capacity of 6A @ 12V == 72W min to power a chartplotter, more if the CP's power spec suggested it.

Boo2

Depends what plotter you have. Thats why i said there are a range of specs available.
The CP manual should list the max and continuous draw.
 

pvb

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Most plotters will work down to about 10v. If the OP's plotter is turning off, there's either a big wiring problem or the batteries aren't adequate.
 
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